The present invention relates to an indication position calculation mark unit.
An indication position calculation system that calculates an indication position of an indicator on an indication surface (e.g., monitor or screen), such as a shooting game system using a gun-type controller or a presentation system using a pointing device, has been known. In such an indication position calculation system, two indication position calculation marks (e.g., infrared light sources) are disposed near the indication surface. The marks are imaged using a light-receiving sensor provided on the end of the indicator, and the indication position of the indicator on the indication surface is calculated based on the positions of the marks in the image. Japanese Patent No. 2961097 discloses such technology, for example.
In such an indication position calculation system, the marks must be disposed near the indication surface. When forming an indication position calculation system using a general-purpose monitor, screen, or the like, the marks are placed at the top of the monitor, screen, or the like. However, a flat-screen monitor (e.g., liquid crystal monitor) generally does not have an upward surface on which the marks can be placed. Therefore, the marks may be attached near the indication surface using a double-sided tape. However, this mark attachment work is troublesome. Moreover, an adhesive mark may remain on the monitor, screen, or the like. A clip may be attached to the mark, and the mark may be clipped on the monitor, screen, or the like. However, a monitor generally does not have a portion on which the mark can be clipped.